Condescending comments, put-downs, and sarcasm reduce employees’ self-control, which can lead them to behave badly, as well.

“People who are recipients of incivility at work feel mentally fatigued as a result, because uncivil behaviors are somewhat ambiguous and require employees to figure out whether there was any abusive intent,” says Russell Johnson, associate professor of management at Michigan State University. “This mental fatigue, in turn, led them to act uncivil toward other workers. In other words, they paid the incivility forward.”

While curt remarks and other forms of incivility do not involve openly hostile behavior such as bullying and threats, they are a frequent occurrence in the workplace and have a significant effect on employees, the study notes. According to estimates, workplace incivility has doubled over the past two decades and has an average annual impact on companies of $14,000 per employee due to loss of production and work time.

For the study, 70 employees filled out a survey relating to incivility and its effects three times a day for 10 consecutive workdays. Interestingly, the researchers found that “incivility spirals”—when acts of incivility lead to subsequent acts of incivility—can occur unintentionally.

“When employees are mentally fatigued, it is more difficult for them to keep their negative impulses and emotions in check, which leads them to be condescending and rude to colleagues,” Johnson says. “This happens even for employees who desire to be agreeable and polite; they simply lack the energy to suppress curt and impatient responses.”

The study also found that incivility spirals occurred in workplaces that were perceived as political (i.e., where co-workers “do what is best for them, not what is best for the organization”).

“Being the victim of incivility leaves employees depleted because they must expend energy to understand why they were targeted and how to respond,” the study states. This is made more complex in highly political environments where “intentions and motives of others are less clear.”

One way to reduce perceptions of politics, the study says, is to provide clear feedback to employees about desirable types of behavior. “This can be accomplished informally, by enhancing the quality of feedback provided during day-to-day interactions, or more formally via the performance management process.”

The findings appear in the Journal of Applied Psychology. Johnson’s coauthors are from the University of Arkansas, the University of Arizona, and the University of Cincinnati.